Victoria's emergency services commissioner has denied suggestions that authorities lost control of the bushfire response late on the afternoon of Black Saturday.

Bruce Esplin says he does not know what went wrong, but acknowledged that several policies, including the ban on mandatory evacuation, need to be reviewed.

Evidence is mounting at the Royal Commission that suggests services such as the Country Fire Authority and Department of Sustainability struggled to communicate effectively with each other and planning experts as the fires raged.

Today, counsel assisting the commission, Rachel Doyle, asked Mr Esplin if authorities had lost control of the situation by 4:30pm on Black Saturday.

"No, I wouldn't say that," he said.

"I think that there was a huge workload on all the people in that coordination centre, but they were doing everything that they could to control fires across the length and breadth of the state.

"Literally hundreds and hundreds of fires in weather conditions that are probably unprecedented in Victoria's history."

Ms Doyle pointed out to Mr Esplin that at 5:00pm on the day after Black Saturday, his office was issuing out-of-date information regarding Taggerty and Marysville, where 34 people died.